1.\" Copyright (c) 2002-2004 Tim J. Robbins 2.\" All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 13.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 14.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 17.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23.\" SUCH DAMAGE. 24.\" 25.Dd May 21, 2013 26.Dt WCRTOMB 3 27.Os 28.Sh NAME 29.Nm wcrtomb , 30.Nm c16rtomb , 31.Nm c32rtomb 32.Nd "convert a wide-character code to a character (restartable)" 33.Sh LIBRARY 34.Lb libc 35.Sh SYNOPSIS 36.In wchar.h 37.Ft size_t 38.Fn wcrtomb "char * restrict s" "wchar_t c" "mbstate_t * restrict ps" 39.In uchar.h 40.Ft size_t 41.Fn c16rtomb "char * restrict s" "char16_t c" "mbstate_t * restrict ps" 42.Ft size_t 43.Fn c32rtomb "char * restrict s" "char32_t c" "mbstate_t * restrict ps" 44.Sh DESCRIPTION 45The 46.Fn wcrtomb , 47.Fn c16rtomb 48and 49.Fn c32rtomb 50functions store a multibyte sequence representing the 51wide character 52.Fa c , 53including any necessary shift sequences, to the 54character array 55.Fa s , 56storing a maximum of 57.Dv MB_CUR_MAX 58bytes. 59.Pp 60If 61.Fa s 62is 63.Dv NULL , 64these functions behave as if 65.Fa s 66pointed to an internal buffer and 67.Fa c 68was a null wide character (L'\e0'). 69.Pp 70The 71.Ft mbstate_t 72argument, 73.Fa ps , 74is used to keep track of the shift state. 75If it is 76.Dv NULL , 77these functions use an internal, static 78.Vt mbstate_t 79object, which is initialized to the initial conversion state 80at program startup. 81.Pp 82As certain multibyte characters may only be represented by a series of 8316-bit characters, the 84.Fn c16rtomb 85may need to invoked multiple times before a multibyte sequence is 86returned. 87.Sh RETURN VALUES 88These functions return the length (in bytes) of the multibyte sequence 89needed to represent 90.Fa c , 91or 92.Po Vt size_t Pc Ns \-1 93if 94.Fa c 95is not a valid wide character code. 96.Sh ERRORS 97The 98.Fn wcrtomb , 99.Fn c16rtomb 100and 101.Fn c32rtomb 102functions will fail if: 103.Bl -tag -width Er 104.It Bq Er EILSEQ 105An invalid wide character code was specified. 106.It Bq Er EINVAL 107The conversion state is invalid. 108.El 109.Sh SEE ALSO 110.Xr mbrtowc 3 , 111.Xr multibyte 3 , 112.Xr setlocale 3 , 113.Xr wctomb 3 114.Sh STANDARDS 115The 116.Fn wcrtomb , 117.Fn c16rtomb 118and 119.Fn c32rtomb 120functions conform to 121.St -isoC-2011 . 122